ESA’s New Mars Orbiter Prepares For First Science

ESA’s New Mars Orbiter Prepares For First Science

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Trace Gas Orbiter instruments. ESA

The ExoMars orbiter is preparing to make its first scientific observations at Mars during two orbits of the planet starting next week.

The Trace Gas Orbiter, or TGO, a joint endeavour between ESA and Roscosmos, arrived at Mars on 19 October. It entered orbit, as planned, on a highly elliptical path that takes it from between 230 and 310 km above the surface to around 98 000 km every 4.2 days.

The main science mission will only begin once it reaches a near-circular orbit about 400 km above the planet’s surface after a year of ‘aerobraking’ – using the atmosphere to gradually brake and change its orbit. Full science operations are expected to begin by March 2018.

But next week provides the science teams with a chance to calibrate their instruments and make the first test observations now the spacecraft is actually at Mars.

In fact, the neutron detector has been on for much of TGO’s cruise to Mars and is currently collecting data to continue calibrating the background flux and checking that nothing changed after the Schiaparelli module detached from the spacecraft.

It will measure the flow of neutrons from the martian surface, created by the impact of cosmic rays. The way in which they are emitted and their speed on arriving at TGO will tell scientists about the composition of the surface layer.

In particular, because even small quantities of hydrogen can cause a change in the neutron speed, the sensor will be able to seek out locations where ice or water may exist, within the planet’s top 1–2 m.

TGO’s first image of Mars – 13 June 2016. ESA.

TGO’s first image of Mars – 13 June 2016. ESA.

The orbiter’s other three instruments have a number of test observations scheduled during 20–28 November.

During the primary science mission two instrument suites will make complementary measurements to take a detailed inventory of the atmosphere, particularly those gases that are present only in trace amounts.

Of high interest is methane, which on Earth is produced primarily by biological activity or geological processes such as some hydrothermal reactions.

The measurements will be carried out in different modes: pointing through the atmosphere towards the Sun, at the horizon at sunlight scattered by the atmosphere, and looking downwards at sunlight reflected from the surface. By looking at how the sunlight is influenced, scientists can analyse the atmospheric constituents.

In the upcoming orbits there are only opportunities for pointing towards the horizon or directly at the surface. This will allow the science teams to check the pointing of their instrument to best prepare for future measurements.

There is the possibility that they might detect some natural nightside airglow – an emission of light in the upper atmosphere produced when atoms broken apart by the solar wind recombine to form molecules, releasing energy in the form of light.

During the second orbit, the scientists have also planned observations of Phobos, the larger and innermost of the planet’s two moons.

Finally, the camera will take its first test images at Mars next week. In each of the two orbits, it will first point at stars to calibrate itself for measuring the planet’s surface reflectance.

Then it will point at Mars

Given the current elliptical orbit, the spacecraft will be both closer to and further from the planet than during its main science mission. Closest to the planet, it will be travelling faster over the surface than in its final circular orbit, which presents some challenges in timing when the images should be taken.

How TGO's camera takes stereo images. Copyright University of Bern

How TGO’s camera takes stereo images. Copyright University of Bern

The camera is designed to capture stereo pairs: it takes one image looking slightly forwards, and then the camera is rotated to look ‘back’ to take the second part of the image, in order to see the same region of the surface from two different angles. By combining the image pair, information about the relative heights of the surface features can be seen.

Next week, the camera team will be checking the internal timing to help programme commands for future specific scientific observations. The high speed and changing altitude of the elliptical orbit will make stereo reconstruction challenging, but the team will be able to test the stereo rotation mechanism and the various different camera filters, as well as how to compensate for spacecraft orientation with respect to the ground track.

There are no specific imaging targets in mind, although near the closest approach of the first orbit the orbiter will be flying over the Noctis Labyrinthus region and it will attempt to obtain a stereo pair. In the second orbit, it has the opportunity to capture images of Phobos.

Ultimately, the camera will be used to image and analyse features that may be related to the trace gas sources and sinks, to help better understand the range of processes that may be producing the gases. The images will also be used for looking at future landing sites.

“We’re excited we will finally see the instruments perform in the environment for which they were designed, and to see the first data coming back from Mars,” says Håkan Svedhem, ESA’s TGO Project Scientist.

After this brief science instrument demonstration period, which also serves as a test for relaying this data back to Earth, along with data from NASA’s Curiosity and Opportunity rovers, the focus turns back to operations and the preparations required to for aerobraking next year.

Source: ESA

Gaia’s Billion Star Map Hints At Treasures To Come

Gaia’s Billion Star Map Hints At Treasures To Come

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Gaia’s first sky map. Source: ESA

The first catalogue of more than a billion stars from ESA’s Gaia satellite was published today – the largest all-sky survey of celestial objects to date.

On its way to assembling the most detailed 3D map ever made of our Milky Way galaxy, Gaia has pinned down the precise position on the sky and the brightness of 1142 million stars.

As a taster of the richer catalogue to come in the near future, today’s release also features the distances and the motions across the sky for more than two million stars.

“Gaia is at the forefront of astrometry, charting the sky at precisions that have never been achieved before,” says Alvaro Giménez, ESA’s Director of Science.

Gaia mapping the stars of the Milky Way. Source: ESA.

Gaia mapping the stars of the Milky Way. Source: ESA.

“Today’s release gives us a first impression of the extraordinary data that await us and that will revolutionise our understanding of how stars are distributed and move across our Galaxy.”

Launched 1000 days ago, Gaia started its scientific work in July 2014. This first release is based on data collected during its first 14 months of scanning the sky, up to September 2015.

“The beautiful map we are publishing today shows the density of stars measured by Gaia across the entire sky, and confirms that it collected superb data during its first year of operations,” says Timo Prusti, Gaia project scientist at ESA.

Source: ESA

Gaia’s Billion-Star Map Hints At Treasures To Come

Gaia’s Billion-Star Map Hints At Treasures To Come

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Gaia’s first sky map. Source ESA/Gaia/DPAC

The first catalogue of more than a billion stars from ESA’s Gaia satellite was published today – the largest all-sky survey of celestial objects to date.

On its way to assembling the most detailed 3D map ever made of our Milky Way galaxy, Gaia has pinned down the precise position on the sky and the brightness of 1142 million stars.

As a taster of the richer catalogue to come in the near future, today’s release also features the distances and the motions across the sky for more than two million stars.

“Gaia is at the forefront of astrometry, charting the sky at precisions that have never been achieved before,” says Alvaro Giménez, ESA’s Director of Science.

Artist's impression of Gaia mapping the stars of the Milky Way. Source ESA/ATG medialab; background: ESO/S. Brunier

Artist’s impression of Gaia mapping the stars of the Milky Way. Source ESA/ATG medialab; background: ESO/S. Brunier

“Today’s release gives us a first impression of the extraordinary data that await us and that will revolutionise our understanding of how stars are distributed and move across our Galaxy.”

Launched 1000 days ago, Gaia started its scientific work in July 2014. This first release is based on data collected during its first 14 months of scanning the sky, up to September 2015.

“The beautiful map we are publishing today shows the density of stars measured by Gaia across the entire sky, and confirms that it collected superb data during its first year of operations,” says Timo Prusti, Gaia project scientist at ESA.

Source: ESA

ESA Is Planing To Build A Permanent 3D Print Moon Base By 2030

ESA Is Planing To Build A Permanent 3D Print Moon Base By 2030

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The decade 2020-2030 will see a renewed and sustained international effort to explore Earth’s only natural satellite.

The ESA exploration strategy considers the Moon as the next destination for humans venturing beyond Low Earth Orbit and an integral element of the roadmap towards humans missions to Mars.

This will be a shared journey. New and bold ambitions for lunar exploration call for a new era of coordinated human and robotic missions. Humans and robots are set to explore the Moon together. The ISECG Global Exploration Roadmap underlines the strategic significance of the Moon in a global space exploration endeavour, calling for a shared international vision on how to best accomplish common lunar exploration goals.

vision

The International Space Station programme has demonstrated the importance of a robust international partnership for ISS development, assembly, operations and effective utilisation. Now is the time to build on this partnership and open it to new partners to continue the journey beyond low Earth orbit.

Key to realizing the Lunar Exploration Vision 2030 is the step-wise deployment of an international exploration architecture. This vision envisages access for robots and humans to previously unexplored regions.

Learn more about the ESA Moon Challenge.

Source: ESA